1. Field of the Invention
The present invention relates to a method for preparing graphene ribbons, and particularly, to a method for fabrication of graphene in the form of a ribbon.
2. Background of the Invention
Graphene, a single layer trigonal carbon honeycomb with a thickness of about 4 Å (refer to FIGS. 1 (A) and 1 (B)), has enormous industrial potential due to its outstanding physical properties compared to, among others, in particular single-wall carbon nanotubes. Graphene is the basic unit of C60, multi-walled carbon nanotubes (MW CNTs), and graphite.
The two-dimensional, single layer graphene material is obtainable when the weak van der Waals forces between graphene planes are disrupted. Micromechanical cleavage is the most assured method for fabricating graphene, but the yield is too low. The yield of pure graphene by a chemical route, which has been proposed as a mass production method, is also as low as around 0.5%. Graphene formed on a metal substrate by chemical vapour deposition (CVD) methods produce mostly multiple-layer graphene materials.
On the other hand, there have been efforts to prepare short carbon nanotubes by cutting multi-walled carbon nanotubes (known as a non-crystalline turbostratic structure, refer to FIG. 2) by a mechanical method, such as ball milling, or a chemical method (refer to L. Chen et al., [Materials Letter 60 (2006) 241-244], N. Pierard et al., [Chemical Physics Letters 335 (2001) 1-8], Z. Konya et al., [Carbon 42 (2004) 2001-2008], and Z. Gu et al., [Nano Letter 2 (2002) 1009]). However, graphene could not be obtained by such efforts.